The primate lentiviruses include the human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and simian immunodeficiency viruses (SIVs) (Barre-Sinoussi, F., et al. (1983) Science 220:868-871; Clavel, F. (1987) AIDS 1:135-140; Daniel, M. D., et al. (1985) Science 228:1201-1204; Desrosiers, R. C. (1990) Ann. Rev. Immunol. 8: 557-578; Gallo, R. C, et al. (1984) Science 224:500-503). HIV-1 and HIV-2 infect humans, HIV-1-like viruses infect chimpanzees, and SIV variants infect African monkeys. Humans infected by HIV-1 and HIV-2 and Asian macaques infected by certain SIV strains often develop life-threatening immunodeficiency due to depletion of CD4-positive T lymphocytes (Fauci, A., et al. (1984) Ann. Int. Med. 100:91-106; Letvin, N. L., et al. (1985) Science 230:71-739, 19).
In humans, HIV infection causes Acquired Immunodeficiency Syndrome (AIDS), an incurable disease in which the body's immune system breaks down leaving the victim vulnerable to opportunistic infections, e.g., pneumonia and certain cancers, e.g., Kaposi's Sarcoma. AIDS is a major global health problem. The Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that there are now over 34 million people living with HIV or AIDS worldwide; some 28.1 million of those infected individuals reside in impoverished subSaharan Africa. In the United States, approximately one out of every 500 people are infected with HIV or have AIDS. Since the beginning of the epidemic, AIDS has killed nearly 19 million people worldwide, including some 425,000 Americans. AIDS has replaced malaria and tuberculosis as the world's deadliest infectious disease among adults and is the fourth leading cause of death worldwide. There remains a need for the identification of inhibitors of retroviral infection. To this end, there also remains a need for the development of methods for the identification of such inhibitors.